JP2527746B2 - Tape recorder device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to partial rewriting of a signal track recorded on a magnetic tape as a recording medium in a tape recorder device, particularly a rotary head type tape recorder device ( Af
The present invention relates to a tape recorder device capable of minimizing the collapse of the linearity of a track that occurs when performing ter recording (hereinafter referred to as dubbing).

[Prior Art] Some rotary head type magnetic recording / reproducing devices perform A / D conversion of an input audio signal and record it on a magnetic tape in the form of a digital signal. At the time of reproduction, the digital signal recorded on the magnetic tape is recorded. A rotary head type digital audio tape recorder (Rotary head type Digita) that performs D / A conversion and returns to the original analog audio signal for output.
l Audio Tape-recorder, hereinafter referred to as R-DAT).

FIG. 3 is a diagram showing a partial outline of R-DAT. In the figure, R-DAT uses a small diameter drum (1) with a diameter of 30 mm,
Two rotary heads A (+ azimuth heads) (2a) and two rotary heads B (-azimuth heads) (2b) with different azimuth angles are made to face each other by 180 ° and attached to the drum (1), and the tape (3) is attached. It is wound around a drum (1) at 90 ° and a signal of a track format as shown in Fig. 4 described later is recorded without a guard band.

FIG. 4 is a diagram showing a track format of R-DAT. In the figure, (4) is a PCM consisting of 128 blocks.
The PCM area for recording the converted audio signal, (5a) and (5b) are the ATF areas in which the signals for tracking during reproduction are each composed of 5 blocks, and (6a) and (6b) are It is a sub-code area for recording additional information such as music number and time information, each consisting of 8 blocks. During playback, the tracking error signal, which is a signal for tracking the signal track, is generated by the signals recorded in the ATF areas (5a) and (5b), and track tracking is performed so that the tracking error signal becomes zero. Be seen.

FIG. 5 is a diagram showing signal recording patterns of the ATF areas (5a) and (5b) in FIG. In the figure, (7) is a pilot signal f1, which generates a tracking error signal. (8) and (9) are sync signals f2 and f3, respectively, which are used as timing detection signals for generating tracking error signals. The sync signal f2 (8) is on the A track (+ azimuth track), and the sync signal f3 (9) is on the B track (-azimuth track).
The signal recording pattern is recorded on each track, and the recording length is changed to 0.5 block length and 1 block length for every two tracks, and the signal recording pattern is completed in four tracks. For this reason, the tracks can be easily identified, and it is considered to prevent tracking over adjacent tracks next to each other during normal reproduction. (10) is the pilot signal
An erase signal f4 for erasing f1 (7) and sync signals f2 (8) and f3 (9).

The conventional tape recorder device is configured as described above,
Sync signal f2 (8) or f3 during normal playback
At the same time that (9) is detected, the pilot signal f1 (7) level of the right adjacent track is detected, and after a certain time has elapsed, the pilot signal f1 (7) level of the left adjacent track is detected and the left and right pilot signal f1 is detected. A tracking error signal is generated by taking the difference between the detection levels in (7). The tracking is performed so that the detection level difference between the left and right pilot signals f1 (7) becomes zero, in other words, the head scans the center of the track.

Since the R-DAT is recorded in the track format shown in Fig. 4, while performing ATF tracking, PCM
The system makes it easy to partially rewrite the area (4) and subcode areas (6a) and (6b), that is, post-recording. When the PCM area (4) is post-recorded while generating the tracking error signal during normal playback, R-DA
In T, since a head with a width 1.5 times wider than the track width is usually used, as shown in FIG. 6, a post-recorded portion (PCM area (4)) and a non-post-recorded portion (ATF area (5a), ( In 5b) and subcode areas (6a) and (6b)), the linearity of the tracks is impaired by the amount that the head is applied to an adjacent track (usually, equivalent to 1/4 track width). In order to avoid this, at the time of after-recording, it is possible to carry out the tracking by off-tracking corresponding to a predetermined 1/4 track width as shown in FIG.

[Problems to be Solved by the Invention] In the conventional tape recorder as described above, in order to ensure the linearity of the track, when the after-recording mode is ended while the tracking is performed in the state of being off-track by a predetermined amount. As shown in FIG. 7, the post-recorded portion of the track with track number 7 becomes half of the normal track width, and when reproducing, the S / N ratio of the reproduced signal deteriorates and the error rate deteriorates significantly. Therefore, in the worst case, there is a problem that abnormal noise may be generated or muting may occur.

The present invention has been made to solve such a problem, and provides a tape recorder device which does not fall into an abnormal noise or a muting state without significantly narrowing the track width of the post-recorded portion at the end of the post-recording mode. The purpose is to get.

[Means for Solving Problems] A tape recorder device according to the present invention is a rotary head type tape recorder for recording and reproducing using a head having a width wider than a width of a signal track formed on a recording medium. The device is a system control means for outputting a normal reproduction mode / after recording mode switching signal, and an analog switching means for selectively outputting a tracking error signal during normal reproduction or a tracking error signal during after recording according to the mode switching signal. And an after-recording signal generating means,
When the after recording mode is started, the after recording signal is output from the after recording signal generating means, the tracking error signal at the time of after recording is selectively output from the analog switching means, and at the end of the after recording mode,
The tracking error signal at the time of normal reproduction is selectively output from the analog switching means, and the afterrecording signal output from the afterrecording signal generating means is stopped after a predetermined time has elapsed from the end of the afterrecording mode.

[Operation] In the present invention, when the after-recording mode end command is output, the tracking state after a predetermined amount of off-track is returned to the normal tracking state and the after-recording signal is stopped. As described above, the track width of the post-recorded portion is not significantly narrowed, the error rate of the reproduction signal is not greatly deteriorated, and the generation of abnormal noise and the muting state are prevented.

[Embodiment] FIG. 1 is a block diagram showing a tape recorder according to an embodiment of the present invention.

FIG. 2 is a diagram showing tracking states at the start and end of dubbing.

An embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to the drawings. In FIG. 1, when the after-recording mode / normal reproduction mode switching signal (12) output from the system controller (11) becomes high level, for example, the system enters the after-recording mode, and the output signal of the OR gate circuit (13) ( 14) becomes high level, and the after-recording signal generation circuit (15) outputs the after-recording signal (16) in a predetermined area. Further, when the post-recording mode / normal reproduction mode switching signal (12) controls the analog switch circuit (17) and becomes high level, for example, the output side contact is connected to the input side upper contact (H), and The tracking error signal (19b) in the post-recording mode output from the tracking error signal generation circuit (18b) in the mode is transmitted to the contact on the output side, and the tracking state is set to offtrack by a predetermined amount, and the linearity of the track is Avoid being damaged. (In the left half of Fig. 2, after-recording of the track PCM area of track number 1 has started,
It shows a state of gradually shifting to a tracking state in which a predetermined amount is off-tracked. ) Post-recording mode / normal playback mode switching signal (12)
When the level becomes low, the dubbing mode of the system is released, but at the falling edge of the dubbing mode / normal playback mode switching signal (12), the monostable multivibrator (20) has a positive pulse signal (21). Is continuously output for a time corresponding to the pulse width of. On the other hand, since the post-recording mode / normal reproduction mode switching signal (12) has become low level, the output side contact of the analog switch circuit (17) is connected to the input side lower contact (L), The tracking error signal (19a) output from the tracking error generation bottleneck (18a) during normal reproduction is transmitted to the output side contact, and the tracking state in which a predetermined amount of off-track is performed is returned to the normal tracking state without off-track. There is. The width of the output pulse signal (21) of the monostable multivibrator (20) is set to the time from the off-track state to the state without track deviation, and the track number (x ₄ ) shown in Fig. 2 is set. In the above, the post-recording in the PCM area is completed by the head locus that scans the center of the track. Therefore, the track number
Since the track width of the PCM area of the track x ₅ is unnecessary to be narrowed significantly, the error rate of the reproduction signal in this area is not significantly deteriorated.

Although the present invention is applied to R-DAT,
System that partially rewrites, eg 8mm VTR
Obviously, it can be applied to PCM recorders, etc.

[Effects of the Invention] As described above, the present invention is a rotary head type tape recorder device that performs recording and reproduction using a head having a width wider than the width of a signal track formed on a recording medium. System control means for outputting a reproduction mode / after recording mode switching signal, and analog switching means for selectively outputting a tracking error signal during normal reproduction or a tracking error signal during after recording according to the mode switching signal,
After-recording signal generation means is provided, and when the after-recording mode is started, the after-recording signal generation means outputs the after-recording signal, and the analog switching means selectively outputs the tracking error signal at the time of after-recording, and the after-recording mode. At the end point, the tracking error signal at the time of normal reproduction is selectively output from the analog switching means, and after the predetermined time has elapsed from the end point of the afterrecording mode, the afterrecording signal output from the afterrecording signal generating means is stopped. As a result, the track width of the post-recorded portion is not significantly narrowed, and it is possible to avoid an abnormal state such as the generation of abnormal noise.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a tracking state diagram at the start and end of after-recording, FIG. 3 is a partial schematic diagram of R-DAT, and FIG. 4 is R-DAT. FIG. 5 is a track format diagram of FIG. 5, FIG. 5 is a signal recording pattern diagram of an AFT area, and FIG. 6 is a diagram showing a post-recorded portion and a non-post-recorded portion when off-track is not performed,
The figure is a diagram showing a post-recorded portion and a non-post-recorded portion when off-tracking. In the figure, (11) …… System controller, (12)
...... Post-recording mode / normal playback mode switching signal,
(13) …… OR gate circuit, (15) …… Post-recording signal generation circuit, (17) …… Analog switch circuit, (18a)…
... Tracking error signal generation circuit during normal playback, (18
b) ...... Tracking error signal generation circuit in dubbing mode, (20) …… Monostable multivibrator. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (2)

(57) [Claims] 1. A rotary head type tape recorder for recording / reproducing by using a head having a width wider than that of a signal track formed on a recording medium, wherein a normal reproduction mode / after recording mode switching signal is provided. After recording, the system control means for outputting, the analog switching means for selectively outputting the tracking error signal at the time of normal reproduction or the tracking error signal at the time of after-recording according to the mode switching signal, and the after-recording signal generating means are provided. When the mode is started, the after-recording signal generating means outputs an after-recording signal, and the analog switching means selectively outputs a tracking error signal at the time of after-recording, and an after-recording signal. At the end of the recording mode, the tracking error signal during normal reproduction is selectively output from the analog switching means, and after a predetermined time has elapsed from the end of the afterrecording mode, the afterrecording signal output from the afterrecording signal generating means is stopped. A tape recorder device characterized by the following. 2. The predetermined time is equal to or longer than the time required to shift from a predetermined amount of track deviation scanning state to a track deviation free scanning state. Tape recorder device.